Spotlight Interview

Francis Halzen had no intention of staying at the University of Wisconsin Madison; a six month visit turned into a 44 year long career as a professor and researcher here, a university Halzen describes as “one of the greatest, if not the greatest, universities in the world to do science.” Originally born in Belgium, Halzen earned his PhD and already had 3 years of work at the CERN Hadron Collider in Geneva, Switzerland behind him when he came to Wisconsin. He has since enjoyed a successful career as a professor of physics, but his greatest achievements are those in the research field of theoretical particle physics, specifically working with neutrinos.


The neutrino is a non-charged particle very similar in size and mass to an electron. Because they are not subject to electromagnetism that comes with having a charge, they can pass through matter. Other than these simple properties, there is not a copious amount known about neutrinos, making them intriguing to scientists and researchers of particle physics. Halzen is a pioneer in the field, having developed a unique and innovative technology to detect these neutrinos. The system, called the IceCube Neutrino Observatory, is contained within a kilometer cube of ice almost 2 miles deep under south pole. This diagram depicts the massive and intricate nature of the system. This ice is hundreds of thousands of years old and is so completely pure that light can travel in it for over 100 meters, a quality that proved vital in the success of such a system. Within this ice, Halzen and his team placed thousands and thousands of tiny light sensors. When a neutrino is produced, there is a chance, however minute, that it will travel to earth and collide with the nucleus atom. This collision creates a small nuclear reaction, which in turn produces a blue light. This blue light is detected by the light sensors embedded in the ice, and can be used to map the source of the neutrinos. This data is then used to create a sort of ‘map’ of the galaxies; they provide informations from events such as exploding stars or black holes. The IceCube collaboration is the first system of its kind and one of the most important contributions to research on neutrinos ever made. Halzen and his team recently celebrated 5 years of data collecting with this incredible system after 20 long years of conceptualizing and constructing. He shared with us an anecdote of the first round of data the IceCube system ever collected:

We found 28 neutrinos, that was our first time. It’s like a digital picture with 28 points on it. And…we know we have 28 events. And the first one we reconstructed…came one degree from the center of our own galaxy. And so, I went home totally depressed. Because, you know, to build this telescope and what I see is the sun! But it turns out, it takes about day of computing time to analyze these events. And so, after a month of having looked at this, we found, actually, it didn’t really come from the center of our galaxy; they don’t even come from our galaxy at all. They come from outside the galaxy. We have good ideas where they come from, but not definite yet. And so, that’s the excitement. We are accumulating data and getting more and more neutrinos, and eventually, we will see what we will see. There’s no doubt about that.

Professor Halzen is proof that scientific success happens as you go; as he and his team set out at more than 20 years ago, he had no idea if this idea would work. He remembers walking up and down the hallway outside his office asking coworkers if they wanted to be a part of this idea he just had, and being met with overwhelming skepticism. However, today the IceCube is the leading data collection system in the world for this sort of information.
Professor Halzen also shared with us wise words of advice for young scientists and researchers everywhere:

Science is still the domain where contributions are made by young people. So my advice is, don’t wait until you’re old. It’s the only job you can do where you have a big advantage being young, because you haven’t been ‘brainwashed’. Once you’ve been brainwashed, you think the same way as 10,000 other physicists.

So when it comes down to it, if you have an idea go out and make it happen; you never know where you might end up.

By Emma Hazel and Cecelia Moog

2017-05-23T23:31:48+00:00 April 20th, 2016|